Looks like the larger pollen for Betty Prior are around 30 microns. Most of the smaller ones appear to be shrunken which I understand means that they are dead.
Thus it looks like Betty Prior should be successful as a pollen donar with diploid mothers. Help-Me-Find only lists one offspring - Chatter. Chatter is listed as having World’s Fair as the mother and Betty Prior as the father. Herb Swin thought that World’s Fair is a tetraploid. If this is correct then I wouild expect that Chatter would be a triploid. According to Help-Me-Find Chatter does have 4 offspring-Fireflame, Pigmy Red, Sjoukji Dijkstra, and Tommy Bright. Such a limited number of offspring would (in my mind) be consistent with it being a triploid.
I got to see your photos yesterday at the library where they loaded fast. What an excellent adventure!
And I thought I could see the rest at home, but my land line is just too slow.
One thing that came to mind: if you were to use a cover slip, even one of the thicker ones, you’d have a sharper photo that by putting two slides together.
The pollen are colporate, with colpi and pores in the middle of the colpi. (Colpi are the furrows.) The colpi are relatively parallel to each other.
It becomes important to distinguish one pollen grain versus the pollen grains that form adjacent to each other.
As David said, similar treatment is a necessity. Likewise where you measure is important.
(I worked mostly in the Paleozoic, before pollen.) I have a feeling that measurements parallel to the colpi would give you an additional refinement of measures.
I only recently saw the almost century old paper by Ruth Cole “Imperfection of Pollen and Mutability in the Genus Rosa” from Botanical Gazette vol 63 no. 2, Feb 1917 pp. 110-123 that is available through JSTOR search engines at subscribing libraries. I’d be interested if her numbers of non-productive pollen hold from the same species grown in other parts of the country (hers were from the Arnold Arboreteum).
Many of Henry’s pictures can hold their own when compared to hers.
Ann, thank you for your comments. I have not been using cover slips as I have been able to purchase all of the slides I need at a freight salvage store for a very low price. I do have some cover slips left over from my tissue culture days so when I have time I will run some comparison tests.
I purchased a low cost ($30.80) “Graduated Mechanical Stage Micrometer”. It makes the task of positioning so much easier. The mounting pins did not fit the holes on my microscope but they were removeable so I removed them and “super-glued” the unit in place.
Today some red Grootendorst flowers opened. I assumed that it was a triploid but the pollen diameters are mainly around 28-29 microns. Thus, if it is a triploid; it is producing mainly diploid pollen. Help-Me-Find lists a number of offspring; but I have not been able to get any over many years of half hearted attempts. This season I do have one small open pollinated red hip forming.
Today I found the exact brand, model microscope that I purchased used at least 10 years ago for sale on the internet for $100.
It is a zoom with stops only at the 2 extremes: 100X and 500X. I found it very easy to modify for a web cam. The 2 extreme positions hold their calibration. I put in a new slide, use the 100X position to look for suitable pollen. I then start “zooming”, keeping the selected pollen on the computer screen by first slight movements of the slide and now with the micrometer (much easier). I do this until I reach the 500X setting. I then use the free “Micam” computer program to measure the pollen.
I may make one modification - I may replace the tungston standard light source with a white LED light source.
Robert I have Home Run. Last year (my first with it), it bloomed very well. This year I only got a few blooms all season. It has not produced any blooms since I set up the microscope.
I have changed the light source from tungsten to white LCD.
The following pictures of (Sir Thomas Lipton OP) pollen illustrate the improvement:
When a pollen grain is not viable, it is expected to not absorb the red dye. The white LCD light appears to be very useful for seeing this difference between stained and unstained pollen.
So far none of my Home Run hybrids are setting hips. This makes me wonder if they are also triploids. Inability to set hips could be a function of immaturity.
Mike Fitts also told me that Home Run bloomed poorly for him this season in Ohio.
I dont find Home Run to be a great bloomer (which is why I crossed it to Cherry Meidiland). I have it next to Baby Love, which is easily a larger plant than Home Run, and blooms at least x10 more in terms of color per square inch per season (I think in these terms due to landscaping lol).
I got a Home Run at a plant sale in early June and we’ve had drought ever since. Home Run is sitting on my mist table with other plants that haven’t made it into the ground yet and has been in continuous bloom. Maybe moisture in the air and consistant wetness are its friends.
On the color of light for microscope illumination. Back when microscopes were new, thin sections of rock were being studied, among many things. This was being done by day light in England, so colors reported were for that light.
Then came electricity. And to standardize illumination color, the addition of a blue filter between the light source and the thing illuminated gives the non-orange/tan tinted light that I see without it.
I look forward to getting to the library tomorrow to see more of Henry’s images.
Thanks Ann for the information about the blue filter. I checked and mine had one so I removed it. The free computer program that I use (Micam) has controls for brightness, color balance, etc.
I found a 1.3 megapixel webcam with a CCD sensor (which is supposed to be better than a CMOS sensor) at a flea market for $18.00 (a Logitech Pro 4000). The link below gives a measurement of Nearly Wild pollen. Often I see a ring around a pollen. Does anyone know if I should be measuring from the inside of the ring or from the outside? In this case it would change the diameter from about 28 microns to about 32 microns.
I think the pollen exine is separating from the body of the individual pollen grain.
Henry or David, is this a result of the use of the stain? As I said before, I never looked much at modern palynomorphs, only acid resistant microfossils from rocks. I’m not even sure if there are protocols governing measurements.
Looks like Yellow Flower Carpet is a very infertile triploid. The links below are to what appears to be a healthy diploid pollen grain and a healthy tetraplod pollen grain, but most grains did not take up the stain.
Hi Timo, In the Spring 2004 RHA newsletter I have a few page article taking a person through chromosome counting step by step with pictures. In the article I highlight the modifications I learned to use to make it easier to count rose chromosomes. Henry’s link is nice. For many general biology classes onions and other Liliaceae species are often used because of their large chromosomes or grass members like Barley are used. Roses have smaller chromosomes and sometimes finding cells at the right stage and softening them to spread them can be more challenging in some species than others. In the article I compare and show a picture of Easter lily chromosomes to roses and have specifically pictured cells showing ‘Carefree Sunshine’, ‘De Montarville’, and ‘Dorcas’ are tetraploid.